PARIS — Eutelsat has switched this year’s planned launch of its W3B telecommunications satellite from a Chinese Long March vehicle to a European Ariane 5 rocket amid concerns about an insufficient supply of the non-U.S. components that would permit the satellite’s export to China, Eutelsat and W3B prime contractor Thales Alenia Space said Feb. 18.

Paris-based Eutelsat will instead use China’s Long March vehicle to launch the W3C satellite — a nearly identical copy of W3B, also under construction at Thales Alenia Space — in mid-2011, when the parts-related concerns are expected to have eased, the two companies said.

U.S. technology export rules, known as the International Traffic in Arms Regulations (ITAR), for the past 10 years have been enforced in such a way as to prohibit U.S.-built satellites or satellite components from being exported to China. In response, Thales Alenia Space has developed what has become known as an “ITAR-free” satellite product, so named because it carries no components subject to the U.S. rules and thus can be shipped to China for launch.

W3B and W3C were both contracted as ITAR-free satellites. But an April 2009 earthquake in L’Aquila, Italy, that badly damaged a Thales Alenia Space satellite-electronics plant caused the company to fall behind in the scheduled delivery of components for the W3B satellite, whose launch had been set for between March and June 2010.

That delay pushed the W3B satellite’s delivery to July, with a launch around August or September on the Chinese vehicle.

But in recent months, Eutelsat’s need for an early launch of W3B has grown as the company, already facing high demand across its in-orbit fleet, suffered the loss of a couple of spacecraft that exacerbated the strains on its capacity.

In January, Thales Alenia Space and Eutelsat agreed that the manufacturer would have trouble ensuring that it had sufficient W3B spares on hand in the event that one or another component needed to be replaced at the last minute. It is not unheard of for satellite builders to replace components even after the satellite arrives at its launch base.

Emmanuel Grave, Thales Alenia Space executive vice president for telecommunications programs, said the availability concern extended beyond Italian-built components to other non-U.S. parts.

But Thales Alenia Space did have sufficient supplies of U.S.-built components, which are used on most of the company’s satellites that do not require the ITAR-free designation.

Grave said the company will still deliver W3B as planned in July, with the ITAR-free components on board. But the manufacturer likely will bring some U.S.-built spares to the Ariane 5 launch site, at Europe’s Guiana Space Center in French Guiana.

“This shift is a simple matter of risk reduction on our part and on Eutelsat’s part,” Grave said in an interview.

Meanwhile, Thales Alenia Space has redistributed component-production capacity to other plants as it awaits full reconstruction of the L’Aquila site. Grave said that production flow has resumed and that a mid-2011 launch of W3C on a Chinese rocket presents no components-related problems.

Eutelsat Chief Executive Michel de Rosen, in a Feb. 18 conference call with investors, said he visited Beijing several weeks ago to inform the Chinese launch services provider, China Great Wall Industry Corp., and its parent company, China Aerospace Corp., of Eutelsat’s decision to exercise a contract option to swap the W3B for W3C, and to move the Long March launch to mid-2011.

Eutelsat officials did not spell out during the conference call how much more they are paying for the Ariane 5 launch by Europe’s Arianespace consortium than they would have paid for the Chinese launch.

A launch on the Ariane 5 will mean the 5,400-kilogram W3B will share space under the Ariane 5 fairing with another, smaller telecommunications satellite, rather than being a sole passenger as would have been the case aboard a Long March rocket.

Peter B. de Selding was the Paris bureau chief for SpaceNews.